Properties Of Polycaprolactone Research Articles

Fabrication and Characterization of Polycaprolactone-Baghdadite Nanofibers by Electrospinning Method for Tissue Engineering Applications.

This work investigates the essential constituents, production methods, and properties of polycaprolactone (PCL) and Baghdadite fibrous scaffolds. In this research, electrospinning was used to produce fiber ropes. In this study, the Baghdadite powder was synthesized using the sol-gel method and incorporated into PCL's polymeric matrix in formic acid and acetic acid solvents. The present work examined PCL-Baghdadite fibrous scaffolds at 1%, 3%, and 5 wt% for morphology, fiber diameter size, hydrophilicity, porosity, mechanical properties, degradability, and bioactivity. The introduction of Baghdadite nanopowder into pure PCL scaffolds reduced fiber diameter. The wetting angle decreased when Baghdadite nanopowder was added to fibrous scaffolds. Pure PCL reduced the wetting angle from 93.20° to 70.53°. Fibrous PCL scaffolds with Baghdadite nanopowder have better mechanical characteristics. The tensile strength of pure PCL fibers was determined at 2.08 ± 0.2 MPa, which was enhanced by up to 3 wt% by adding Baghdadite nanopowder. Fiber elasticity increased with tensile strength. Baghdadite at a 5% weight percentage reduced failure strain percentage. Fibers with more Baghdadite nanopowder biodegrade faster. Adding Baghdadite ceramic nanoparticles resulted in increased bioactivity and caused scaffolds to generate hydroxyapatite. The results show that Baghdadite PCL-3 wt% fibers have promising shape, diameter, and mechanical qualities. After 24 h, L-929 fibroblast cell viability was greater in the scaffold with 3% Baghdadite weight compared to the pure PCL. PCL-3 wt% Baghdadite fibers generated hydroxyapatite on the surface and degraded well. Based on the above findings, PCL fibers having 3 wt% of Baghdadite are the best sample for tissue engineering applications that heal flaws.

Biocompatible implants in orthopedics: bone tissue engineering

Introduction Technological advances in bone tissue engineering have improved orthopaedic implants and surgical techniques for bone reconstruction. This approach allows overcoming inconvenience of the paucity of autologous materials available and donor site morbidity.Aim To demonstrate advances of the past 30 years in the development of bioimplants providing alternatives to bone grafting in reconstructive orthopaedics.Methods Preparing the review, the scientific platforms such as PubMed, Scopus, ResearchGate, RSCI were used for information searching. Search words or word combinations were bioactive osteoinductive implants, bone grafting, bone reconstruction, hydroxyapatite, bone scaffolds.Results The main trends in tissue engineering in the field of orthopaedics are represented by construction of three-dimensional structure implants guiding cell migration, proliferation and differentiation as well as mechanical support. Association with bone morphogenetic proteins, growth factors enables proliferation and differentiation of cell types of the targeted bone tissue. A promising advancement should be biodegradability with a controllable degradation rate to compliment cell/tissue in-growth and maturation in limb reconstruction.Discussion This review presents and discusses the experimental and clinical application of biotolerant, bioinert and bioactive materials for reconstructive bone surgery. Future generations of biomaterials are designed to be osteoconductive and osteoinductive.Conclusion Properties of polycaprolactone (PCL) filled with hydroxyapatite (from 10 to 50 wt %) make this hybrid material with controllable absorption a promising strategy for reconstructive surgery in comparison to other materials.

Study on Mechanical Properties of Polycaprolactone Modified Cement-Based Material

With the continuous development of economy, engineering construction is developing towards deep high-stress area, and the problems of large-deformation engineering are becoming more and more serious. Anchoring grouting is a very effective support reinforcement method. The anchoring grouting materials used in the project are mainly cement paste and cement mortar. The characteristics of the grouting material have a decisive influence on the grouting effect. However, it is difficult for the existing grouting materials to satisfy the requirements of strength and deformation at the same time, and improvement is urgently needed. Polycaprolactone (PCL) is an organic polymer material of good engineering properties, including high ductility, good stability and strong impact resistance. In this paper, PCL was added as an auxiliary additive to cement-based materials innovatively, and the mechanical test and micro-test of PCL-cement-based materials were carried out. The results show that adding PCL can significantly increase the compressive strength of cement paste. By adjusting the content of PCL, the strength and ductility of cement mortar can be effectively improved. When the content of PCL is 15%, ideal high performance cement mortar material can be obtained. Anchor grouting is a very effective reinforcement and support method.

The effect of nanocomposite synthesis and the drying procedure of graphene oxide dispersion on the polycaprolactone/graphene oxide nanocomposite properties

In this work, we compare how the properties of polycaprolactone (PCLO) nanocomposites are affected by the method of nanocomposite synthesis and the differences in graphene oxide (GO) properties. PCLO nanocomposites with freeze-dried or hot-dried graphene oxide (FGO/HGO) were synthesized by in situ polymerization and melt mixing. The PCLO molar masses remained constant during melt mixing, but they were significantly reduced with increasing amount of GOs during in situ polymerization. Despite this fact, the in situ polymerized nanocomposites showed enhancement in Young modulus up to 45%, compared to only 10% modulus increase of melt-mixed nanocomposites. This was attributed to the higher crystallinity and the higher level of nanofiller dispersion and exfoliation in in situ polymerized nanocomposites. When comparing the effect of FGO and HGO on nanocomposites properties, the improved dispersion and ameliorated mechanical properties were observed for the former one.

Prediction of the structure and mechanical properties of polycaprolactone–silica nanocomposites and the interphase region by molecular dynamics simulations: the effect of PEGylation

Polymer/silica (PS) nanocomposites are, among numerous combinations of inorganic/organic nanocomposites, one of the most important materials reported in the literature and have been employed in a wide variety of applications. Due to this great interest in the scientific and industry community, knowledge about their physiochemistry allows for a better understanding of their development and improvement. One area of interest found in biopolymers is silica, where silica nanoparticles can be used to increase their mechanical properties and give them higher opportunities to replace synthetic plastics. With this aim in mind, molecular dynamics (MD) simulations were used to predict the structure and mechanical properties of the interphase region and nanocomposite systems of polycaprolactone (PCL), a common poly(hydroxy acid) type biopolymer, reinforced with silica nanoparticles. Two types of nanoparticles were studied to assess the effect of PEGylation: hydroxyl (ungrafted) and polyethylene glycol (PEG) (grafted or PEGylated) functionalized silica. The interaction energy between the nanoparticle and the polymeric matrix was determined, showing an increase of the affinity between each component due to the PEGylation of the nanoparticle. Through the analysis of polymer density profiles, the structure and thickness of the interphase region were determined, and it was observed that PEGylation increased the interphase thickness from 10.80 Å to 13.04 Å while it decreased the peak and average polymer density of the interphase region. Using compressed and expanded molecular models of the neat PCL polymer, the mechanical properties of the interphase region were related to its density through an interpolation model, and mechanical property profiles were obtained, from which the average values of the Young's modulus, Poisson's ratio and shear modulus of the interphase region were calculated. Finally, the mechanical properties of the nanocomposites were determined by molecular mechanics simulations, showing that the silica nanoparticles increased the stiffness of the composite system to about 7-8% with respect to that of the neat polymer, having a 2.09% weight of bare silica or 2.82% weight of PEGylated silica. PEGylation did not show an additional effect on the overall mechanical properties. A mean field micromechanics model (Mori-Tanaka) corroborated the properties calculated for the interphase region using MD simulations. It was concluded that the PEGylation of the nanoparticle improved the affinity, and thus the dispersion, of the silica nanoparticles towards the PCL matrix, but with no further increase in the mechanical properties of the composite.

Effect of sequential electrospinning and co-electrospinning on morphological and fluid mechanical wall properties of polycaprolactone and bovine gelatin scaffolds, for potential use in small diameter vascular grafts

BackgroundNowadays, the engineering vascular grafts with a diameter less than 6 mm by means of electrospinning, is an attracted alternative technique to create different three-dimensional microenvironments with appropriate physicochemical properties to promote the nutrient transport and to enable the bioactivity, dynamic growth and differentiation of cells. Although the performance of a well-designed porous wall is key for these functional requirements maintaining the mechanical function, yet predicting the flow rate and cellular transport are still not widely understood and many questions remain open about new configurations of wall can be used for modifying the conventional electrospun samples. The aim of the present study was to evaluate the effect of fabrication techniques on scaffolds composed of bovine gelatin and polycaprolactone (PCL) developed by sequential electrospinning and co-electrospinning, on the morphology and fluid-mechanical properties of the porous wall.MethodologyFor this purpose, small diameter tubular structures were manufactured and experimental tests were performed to characterize the crystallinity, morphology, wettability, permeability, degradability, and mechanical properties. Some samples were cross-linked with Glutaraldehyde (GA) to improve the stability of the gelatin fiber. In addition, it was analyzed how the characteristics of the scaffold favored the levels of cell adhesion and proliferation in an in vitro model of 3T3 fibroblasts in incubation periods of 24, 48 and 72 h.ResultsIt was found that in terms of the morphology of tubular scaffolds, the co-electrospun samples had a better alignment with higher values of fiber diameters and apparent pore area than the sequential samples. The static permeability was more significant in the sequential scaffolds and the hydrophilic was higher in the co-electrospun samples. Therefore, the gelatin mass losses were less in the co-electrospun samples, which promote cellular functions. In terms of mechanical properties, no significant differences were observed for different types of samples.ConclusionThis research concluded that the tubular scaffolds generated by sequential and co-electrospinning with modification in the microarchitecture could be used as a vascular graft, as they have better permeability and wettability, interconnected pores, and a circumferential tensile strength similar to native vessel compared to the commercial graft analyzed.

Wettability, Thermal Stability, and Antibacterial Properties of Polycaprolactone /ZnO Nanocomposites in Packaging

Polycaprolactone is one of the natural biodegradable polymers mainly used in bioplastics production for packaging, usually composed of non-toxic compounds and biodegradable. The aim was to examine the role of zinc oxide (ZnO) nanopowder on the,wettability , thermal and anti-bacterial effect nanocomposites. Pure PCL and PCL-based bio- nanocomposites doped with various ratios of ZnO nanoparticles from 0% to 5wt% were prepared through the arrangement of throwing procedure. The results show that wettability properties in relation to ideal PCL and that they were increasingly hydrophobic from 57º.8 to 69º.53 because add ZnO nanocomposites,the thermal stability between 300 and 400 ° C makes them perfect for the application of food packaging application. Also, anti-bacterial screening against Gram-positive and Gram-negative microorganisms, which was highly variable and evident in comrades, was compared with PCL.

The Influence of Mucin-Based Artificial Saliva on Properties of Polycaprolactone and Polylactide.

Polycaprolactone (PCL) and polylactide (PLA) are the two most common biodegradable polymers with potential use in oral applications. Both polymers undergo mainly slow hydrolytic degradation in the human body. However, specific conditions of the oral cavity, like elevated temperature, low pH, and presence of saliva affect the rate of hydrolysis. The study examined the properties of solid samples of PCL and PLA subjected to degradation in phosphate buffered saline (PBS) and artificial saliva (AS) at temperatures of 37 or 42 °C, and pH values 2 or 7.4. A number of tests were performed, including measurement of the degree of swelling, weight loss, molecular weight, differential scanning calorimetry, and thermogravimetry of polymers, as well as hardness and tensile strength. Additionally, topography and stiffness of surfaces using atomic force microscopy are presented. It has been noticed that in the artificial saliva, the processes of polymer degradation occur slightly more slowly, and the effects of temperature and pH are less pronounced. We believe that a layer of porcine gastric mucin from artificial saliva that adsorbed on the surface of polymers may have a key role in the observed differences; this layer resembles protective mucin coating tissues in the oral cavity.

Surface modified SiO2 nanoparticles by thiamine and ultrasonication synthesis of PCL/SiO2-VB1 NCs: Morphology, thermal, mechanical and bioactivity investigations

The influence of silica (SiO2) nanoparticles (NPs) on the properties of polycaprolactone (PCL) was investigated. Due to the intense tendency of SiO2 NPs to aggregation and their high surface energy, the surface of SiO2 NPs was treatment via Vitamin B1 (VB1) as a biosafe coupling agent. Novel PCL/SiO2-VB1 nanocomposites (NC) films by variety of percentage of SiO2-VB1 NPs were prepared under ultrasonic irradiation as an eco-friendly and fast procedure following by casting method. Fourier transform infrared spectroscopy and energy dispersive X-ray analysis exposed the presence of SiO2 NPs into the polymer matrix. A good distribution of the silica into the polymer matrix was detected by microscopic observations and EDX testing. According to the UV–Vis spectra, the absorption of prepared NCs was improved via increasing the amount of SiO2 NPs. PCL/SiO2-VB1 NCs showed more thermal stability compared to the pure polymer. The tensile test was investigated and good arrangement among the experimental data and the predicted flexibility of NCs was obtained. Moreover, PCL/SiO2-VB1 6wt% had noticeable increase values for tensile strength. Finally, in vitro bioactivity investigation designated that by rising SiO2 contents in the NCs, the amount of the hydroxyapatite formed was increased and NC films are bioactive and have a potential to be utilized in bone tissue engineering.

Polycaprolactone/chitosan blends: Simulation and experimental design

The morphologies and properties of polycaprolactone (PCL)/chitosan (CS) blends were studied by experiment and dissipative particle dynamics (DPD) simulation. The simulation predicted the morphologies and dispersion of PCL/CS blends with different PCL/CS ratios. Experiments were performed for characterising morphology, thermal and mechanical properties. Both experimental and DPD simulation results indicated that the PCL/CS blend with weight ratio 90/10 possessed homogeneous morphology with excellent ductility. The study indicated that the combination of experiments and the computer simulation can be an effective way of designing and developing the polymer blends with the tailored properties.

The Processing and Characterization of Polyester/Natural Fiber Composites

The mechanical, thermal, and morphological properties of polycaprolactone (PCL) and bamboo fiber (BF) composites were evaluated. Composites containing maleic anhydride-grafted PCL (PCL-g-MA/BF) exhibited noticeably improved mechanical properties due to better compatibility between the two components in comparison to PCL/BF. The dispersion of BF in the PCL-g-MA matrix was clearly more homogeneous due to the creation of branched and cross-linked macromolecules via reactions between anhydride carboxyl groups in PCL-g-MA and hydroxyl groups in BF. The tensile strength and elongation of the PCL-g-MA/BF composites at break was considerably greater than that of PCL/BF composites. In a soil environment, PCL/BF biodegraded slightly faster than PCL-g-MA/BF. Finally, the PCL-g-MA/BF composites not only provided a plateau tensile strength at break up to 40 wt% BF but also provided more easily processing properties.

Effect of sterilisation by gamma irradiation on the ability of polycaprolactone (PCL) to act as a scaffold material

This paper investigates the effect of sterilisation by gamma irradiation (dose 2.5 Mrad) on the following properties of polycaprolactone (PCL): (1) degradation rate (catalysed by lipase), (2) mechanical properties, (3) the ability of cells to attach and subsequently grow on its surface. Gel permeation chromatography (GPC) was used to determine the effects of gamma irradiation of weight average ( M w) and number average ( M n) molecular weights. Gamma irradiation significantly decreased the rate of degradation, although the rates depended on the initial mass of polymer; it also affected the appearance of the degraded specimens when they were examined by scanning electron microscopy. Irradiation also significantly increased the mechanical yield stress but not the failure stress of PCL. It caused a significant increase in M w and decrease in M n that could be attributed to chain scission and cross-linking. Chondrocyte attachment and growth on PCL was not significantly affected by gamma irradiation.

Analysis of mechanical, thermal, and morphological behavior of polycaprolactone/wood flour blends

AbstractIn the present study, the properties of polycaprolactone (PCL) and wood flour (WF) blends were examined by Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry (DSC), Instron mechanical tester, and scanning electron microscopy (SEM). As for results, the mechanical properties of PCL were lowered obviously, due to the poor compatibility between the two phases, when it was blended with wood flours. A fine dispersion and homogeneity of wood flour in the polymer matrix could be obtained when the acrylic acid grafted PCL (PCL‐g‐AA) was used to replace PCL for manufacture of blends. This better dispersion is due to the formation of branched and crosslinked macromolecules since the PCL‐g‐AA copolymer had carboxyl groups to react with the hydroxyls. This is reflected in the mechanical and thermal properties of the blends. In comparison with pure PCL/WF blend, the increase in tensile strength at break was remarkable for PCL‐g‐AA/WF blend. The PCL‐g‐AA/WF blends are more easily processed than the PCL/WF ones since the former had lower melt viscosity than the latter. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1000–1006, 2004